A novel low-density composite for the absorption of microwaves was prepared by loading La-doped spinel cobalt ferrite (La-CFO) onto biomass carbon (BC) derived from corn stalks using a hydrothermal method. This composite (La-CFO@BC) not only maintained the advantageous properties of low density and abundant porosity, but also exhibited a unique morphology, with La-CFO displaying a carpet-like structure interspersed with dandelion-shaped particles. The incorporation of La-CFO effectively tuned the electromagnetic parameters of the composite, thereby improving its impedance-matching attributes and its ability to absorb microwave radiation. At a frequency of 12.8 GHz for electromagnetic waves and with a thickness of 2.5 mm, La-CFO@BC demonstrated remarkable performance in microwave absorption, attaining a noteworthy minimum reflection (RLmin) of -53.2 dB and an effective absorption bandwidth (EAB) of 6.4 GHz. Furthermore, by varying the thickness of the La-CFO@BC within the range of 1.0 to 5.5 mm, the EAB could be broadened to 13.8 GHz, covering the entire X-band, the entire Ku-band, and a substantial portion of the C-band. This study demonstrated that La-CFO@BC was a promising alternative for electromagnetic wave attenuation, which offered superior performance in microwave absorption.

Intelligent devices, when subjected to multiple interactions, tend to generate electromagnetic pollution, which can disrupt the normal functioning of electronic components. Ferrite, which acts as a microwave-absorbing material (MAM), offers a promising strategy to overcome this issue. To further enhance the microwave absorption properties of ferrite MAM, numerous works have been conducted, including ion doping and combining with other materials. Notably, the microstructure is also key factor that affects the microwave absorption properties of ferrite-based MAM. Thus, this article provides a comprehensive overview of research progress on the influence of the microstructure on ferrite-based MAM. MAMs with sheet and layered structures are also current important research directions. For core-shell structure composites, the solid core-shell structure, hollow core-shell structure, yolk-eggshell structure, and non-spherical core-shell structure are introduced. For porous composites, the biomass porous structure and other porous structures are presented. Finally, the development trends are summarized, and prospects for the structure design and preparation of high-performance MAMs are predicted.

Throughout the entire process of sludge treatment and disposal, it is crucial to explore stable and efficient techniques to improve sludge dewaterability, which can facilitate subsequent resource utilization and space and cost savings. Traditional Fenton oxidation has been widely researched to enhance the performance of sludge dewaterability, which was limited by the additional energy input and the instabilities of Fe2+ and H2O2. To reduce the consumption of energy and chemicals and further break the rate-limiting step of the iron cycle, a novel and feasible method that constructed microbial fuel cell powered electro-Fenton systems (MFCⓅEFs) with ferrite and biochar electrode (MgFe2O4@BC/CF) was successfully demonstrated. The MFCⓅEFs with MgFe2O4@BC/CF electrode achieved specific resistance filtration and sludge cake water content of 2.52 × 1012 m/kg and 66.54 %. Cellular structure and extracellular polymeric substances (EPS) were disrupted, releasing partially bound water and destroying hydrophilic structures to facilitate sludge flocs aggregation, which was attributed to the oxidation of hydroxyl radicals. The consistent electron supply supplied by MFCⓅEFs and catalytically active sites on the surface of the multifunctional functional group electrode was responsible for producing more hydroxyl radicals and possessing a better oxidizing ability. The study provided an innovative process for sludge dewaterability improvement with high efficiency and low energy consumption, which presented new insights into the green treatment of sludge.

Magnetic ferrite nanoparticles (MFNPs) have great application potential in biomedical fields such as magnetic resonance imaging, targeted drugs, magnetothermal therapy and gene delivery. MFNPs can migrate under the action of a magnetic field and target specific cells or tissues. However, to apply MFNPs to organisms, further modifications on the surface of MFNPs are required. In this paper, the common modification methods of MFNPs are reviewed, their applications in medical fields such as bioimaging, medical detection, and biotherapy are summarized, and the future application directions of MFNPs are further prospected.
铁氧体磁性纳米材料（MFNPs）在生物医学领域具有较大应用潜力，如磁共振成像、靶向递药、磁热治疗、基因递送等。MFNPs能够在磁场作用下发生迁移运动，并靶向定位到目标细胞或组织。但是要将MFNPs应用到生物体内，需进一步在MFNPs表面进行修饰。本文对MFNPs常见的修饰方法进行了综述，并总结了它在生物成像、医学检测以及生物治疗等医学领域中的应用，进一步展望了MFNPs的未来应用方向。.

In the present work, mixed-spinel ferrite anchored onto graphitic carbon nitride (GCN) was synthesized for mineralization of antibiotic pollutant from waste water. A Z-scheme g-C3N4/Ni0.5Zn0.5Fe2O4 nano heterojunction was fabricated by three step procedure: pyrolysis, solution combustion and mechanical grinding followed by annealing. The prepared photocatlyst was tested for degradation of Doxycycline (DC) drug under the natural sun light. Results revealed that the prepared heterojunction has maximum degradation efficiency of 97.10% pollutant in 60 min experiment. The Z-scheme heterojunction between g-C3N4 and Ni-Zn ferrite improves the photoinduced charges separation and protection of redox capability and therby increases the photo degradation efficiency. The scavenging experiments suggested that O2-● and h+ as main active species responsible for degradation of the antibiotic. In addition, the dopant variation can drive the shists in band gap and energy band positiong too which makes then excellent candidates for synthesizing tunable heterostructures with organic semiconductors. The work focusses on designing and developing of saimpler but efficient magnetic heterojunctions with superior redox capability for solar powered waste water treatment.

The railway wheel is the key component of high-speed railway train. To assure the safety in service, higher requirements are put forward in this study for the composition, microstructure uniformity, and comprehensive properties of wheel materials. In this paper, the high throughput quantitative distribution characterization methods of composition, microstructure, inclusions and Vickers hardness of high-speed railway wheel materials based on the spark source original position analysis technique, high throughput scanning electron microscope (SEM) combined with image batch processing technology, and automatic two-dimensional quantitative distribution analysis technique of inclusions and micro hardness have been studied. The distribution trend of the content of nine elements, size and quantity of sulfides and oxides, ferrite area fraction, and Vickers hardness from the wheel tread surface to the radial depth of about 50 mm below the surface has been discussed. The influence of inclusions distribution on the element segregation and the effect of rim-chilling process with different water spraying angle on the distribution of microstructure and micro hardness have been investigated. It was found that unsynchronized cooling on both sides of the rim altered the phase behavior of ferrite and pearlite and obvious inhomogeneity distribution of ferrite appeared, which led to the asymmetrical Vickers hardness in areas near or away from the flange. Based on the quantitative characterization of area fraction and micro hardness on the same location of wheel rim, a statistical mapping relationship between ferrite area fraction and Vickers hardness was established.

The magnetic nanochain-like material has been regards as one of the most promising electromagnetic (EM) absorbing material but remains a challenging. Herein, magnetic chain-like ferrite (included Fe3O4, CoFe2O4 and NiFe2O4) are successfully produced through a general solvothermal method, using PVP as the structural-liking agent. Experimental results confirm the ultimate sample possess a 3-dimensional chain-like structure which are constructed by numerous ferrite\'s nanoparticles with ~60 nm in diameter. Their electromagnetic parameters can be also manipulated by such a chain structure, especially the dielectric loss, where a sharply increases can be observed on within a lower filling ratio. It greatly benefits to the EM absorbing property. In this article, the electromagnetic absorption layer made with a lower content of ferrite possess the excellent electromagnetic absorption ability, where the optimized effective absorption band was nearly 6.4 GHz under a thickness of 1.8 mm. Moreover, the filling ratio is only 30 wt%. Our method for designing of chain-like magnetic material can be helpful for producing wideband electromagnetic absorption in a low filling ratio.

A new method for recovering metals from ferritic stainless steel pickling sludge using municipal sludge as a reducing agent is proposed. The effects of temperature, municipal sludge blending ratio, and reaction atmosphere on the recovery characteristics were studied. The migration characteristics of heavy metals (HMs) at different temperatures were also investigated. The results showed that municipal sludge can be used as a reducing agent for metal recovery from pickling sludge. Under optimized conditions (temperature of 650 °C and blending ratio of 5%), the recovery fractions of Fe, Cr, and Ni were 70.1, 53.7, and 60.3%, respectively. The CO2 atmosphere was beneficial for increasing the recovery fraction of the pickling sludge. The migration fractions of Cr, Mn, and Ni were approximately 10%. The migration fractions of Zn, Cu, and Pb, which are semi-volatile HMs, varied significantly with temperature. The migration fractions of Cd and As, which are volatile HMs, could exceed 70%.

The mechanical properties and deformation microstructure of cast 304 Cu-containing austenitic stainless steel at 10-3/s strain rate in the range of 700~1200 °C were studied by Gleeble thermal simulator, metallographic microscope and scanning electron microscope. The results showed that the thermoplasticity of 304 Cu-containing austenitic stainless steel was higher than 60% when the temperature was higher than 1000 °C, and the tensile strength as a whole decreased with the increase in temperature. During the tensile process, the morphology and content of ferrite in the test steel were the main factors affecting the high-temperature thermoplastic of the billet. The inclusions near the fracture and the existence of ferrite at the grain boundary greatly affected the formation of microcracks and holes and the fracture.

A green and facile hydrothermal synthesis approach is proposed for the preparation of nitrogen-doped carbon quantum dots (N-CQDs) with wolfberry. These N-CQDs were developed as a highly sensitive fluorescent \'on-off-on\' switch sensor for the sensing of Fe3+ and l-ascorbic acid (AA). The N-CQDs displayed superior fluorescence characteristics of CQDs with a quantum yield up to 22%. The N-CQDs were demonstrated to selectively react with Fe3+, leading to fluorescence quenching effect, which was successfully used for the detection of Fe3+ with a limit of detection at 3 μmoL•L-1. The addition of AA is supposed to repair the surface defects, and result in the fluorescence recovery. Based on this effect, the strategy of \'on-off-on\' detection of AA was established with a limit of detection at 1.8 μmoL•L-1. Furthermore, the practical application of the detection of Fe3+ lake water and AA in medical tablet was demonstrated, promising an effective and efficient \'on-off-on\' nanosensor with low-cost, green synthesis for Fe3+ and AA detection.